RSS ( Really Simple Syndication ) is used with weblogs and newssites to stay up-to-date with the published content. Weblogs are maintained by software, like this blog with WordPress. This software generates besides the HTML-output automatically an RSS-output.

RSS-files can be processed by special RSS-readers.
An example of such an ( open source ) RSS Reader is FeedReader ( a simple Windows application ).
Microsoft has added functionality in Outlook to process RSS-feeds.
Apple has the same functionality in Safari and Mail.

Henny’s weblog RSS-feed:
http://vanderpol-consulting.com/weblog/feed